The present invention relates to a swing-door gate valve for opening and closing an opening of a chamber.
A swing-door gate valve opens an opening of a chamber by moving a gate for closing the opening to a side position, so that a work or the like is taken in and out of the chamber. In the swing-door gate valve as described above, when the gate is brought into contact with or separated from the opening of the chamber, unless the gate is brought into contact with or separated from a sealing surface vertically in a state in which the gate is fronted to the opening of the chamber, a slide occurs between a sealing material provided at the gate and the sealing surface of the chamber, resulting in occurrence of abrasion or dust due to their frictional slide.
However, there is a lot of difficulty to realize a mechanism for performing contact/separation of the gate in a vertical direction relative to the chamber sealing surface and for moving it between a position facing the opening of the chamber and a position retreated aside with a simple and cheap configuration.
A technical object of the present invention is to realize the contact/separation of the gate in the vertical direction relative to the chamber sealing surface and the movement between the position facing the opening of the chamber and the retreating position on the side thereof with a simple and cheap mechanism in the swing-door gate valve.
Another technical object of the present invention is to provide a swing-door gate valve in which no slide occurs at a sealing material so that no dust is substantially produced by bringing the gate into contact with and making it separated from the sealing surface of the chamber vertically with a simple mechanism.
Another technical object of the present invention is to provide a swing-door gate valve in which a driving section of the gate has a simple and compact structure to be driven by a single actuator, and also which is cheap and easy to control the driving, and as a result, a signal system can also be simply and cheaply configured. In order to solve the aforesaid problems, the swing-door gate valve according to the present invention is characterized by comprising: an output shaft supported by a machine frame so as to freely advance or recede in an axial direction thereof and also to be freely rotated around the axis; an arm in which a base end is fixed to the output shaft and a top end is extended to a direction perpendicularly crossing to the output shaft; a gate attached to the top end of the arm, for opening and closing the opening of the chamber; an actuator for causing the output shaft to advance and recede in the axial direction thereof; and a direction-changing mechanism for changing the movement of the arm that is moved to the axial direction of the output shaft, following the forward and backward movement of the output shaft, to a swing-direction movement in which the gate at the top end of the arm is moved between the position facing the opening of the chamber and the position retreated to the side of the opening, and a vertical-direction movement in which the gate is moved vertically relative to the opening of the chamber to come into contact with and to be separated from the opening.
The direction-changing mechanism according to the present invention includes a guide groove formed in the machine frame and a cam follower provided at a base end of the arm and which is fit in the guide groove to be movable, wherein the guide groove includes an axial-direction groove that is parallel with the output shaft and a slant-periphery direction groove extending slantly from an end of the shaft-direction groove.
In addition, the gate is preferably attached to the top end of the arm with free movement and the actuator is preferably a fluid pressure cylinder.
In the gate valve having the aforesaid structure, when the actuator is driven, the arm is moved while the direction thereof being controlled by the direction-changing mechanism by the thrust affected to the output shaft, and more specifically, the cam follower is moved along the guide groove via the arm, and thereby the gate is moved between a closing position for closing the opening of the chamber and the retreating position retreated from the opening to the side thereof.
That is, when the gate is located at the position retreated from the opening of the chamber to the side thereof, and which is moved in a direction closing the opening, the gate is first moved to the position fronting onto the opening by the swing of the arm while moving the gate toward the chamber side, and after the gate has reached the position fronting onto the opening, the gate is moved vertically to the sealing surface of the chamber.
On the other hand, when the gate is moved from a state closing the opening to a position at which the opening is opened, the gate performs a reverse operation to the above by the driving of the actuator in a reverse direction, being moved to the position retreated from the opening to the side thereof.
In the aforesaid swing-door gate valve, the contact/separation of the gate in the vertical direction relative to the chamber sealing surface and the movement between the position facing the chamber opening and the retreating position on the side thereof can be realized with a simple, compact, and cheap configuration using a single actuator. In addition, the gate can be brought into contact with and separated from the sealing surface of the chamber vertically, thereby providing a swing-door gate valve in which no slide occurs at the sealing material, thereby producing no dust substantially.
Furthermore, since the aforesaid single actuator is used, the control of the driving is easy, consequently, the signal system can also be configured simply and cheaply.